/*
 * Copyright (C) 2010 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect.testing;

import static com.google.common.collect.testing.features.CollectionFeature.DESCENDING_VIEW;
import static com.google.common.collect.testing.features.CollectionFeature.SUBSET_VIEW;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.collect.testing.DerivedCollectionGenerators.Bound;
import com.google.common.collect.testing.DerivedCollectionGenerators.SortedSetSubsetTestSetGenerator;
import com.google.common.collect.testing.features.Feature;
import com.google.common.collect.testing.testers.NavigableSetNavigationTester;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.NavigableSet;
import java.util.Set;
import java.util.SortedSet;

import junit.framework.TestSuite;

/**
 * Creates, based on your criteria, a JUnit test suite that exhaustively tests a NavigableSet
 * implementation.
 */
@GwtIncompatible
public final class NavigableSetTestSuiteBuilder<E> extends SortedSetTestSuiteBuilder<E>
{
    public static <E> NavigableSetTestSuiteBuilder<E> using(TestSortedSetGenerator<E> generator)
    {
        NavigableSetTestSuiteBuilder<E> builder = new NavigableSetTestSuiteBuilder<>();
        builder.usingGenerator(generator);
        return builder;
    }

    @Override
    protected List<TestSuite> createDerivedSuites(
            FeatureSpecificTestSuiteBuilder<?, ? extends OneSizeTestContainerGenerator<Collection<E>, E>>
                    parentBuilder)
    {
        List<TestSuite> derivedSuites = new ArrayList<>(super.createDerivedSuites(parentBuilder));

        if (!parentBuilder.getFeatures().contains(SUBSET_VIEW))
        {
            // Other combinations are inherited from SortedSetTestSuiteBuilder.
            derivedSuites.add(createSubsetSuite(parentBuilder, Bound.NO_BOUND, Bound.INCLUSIVE));
            derivedSuites.add(createSubsetSuite(parentBuilder, Bound.EXCLUSIVE, Bound.NO_BOUND));
            derivedSuites.add(createSubsetSuite(parentBuilder, Bound.EXCLUSIVE, Bound.EXCLUSIVE));
            derivedSuites.add(createSubsetSuite(parentBuilder, Bound.EXCLUSIVE, Bound.INCLUSIVE));
            derivedSuites.add(createSubsetSuite(parentBuilder, Bound.INCLUSIVE, Bound.INCLUSIVE));
        }
        if (!parentBuilder.getFeatures().contains(DESCENDING_VIEW))
        {
            derivedSuites.add(createDescendingSuite(parentBuilder));
        }
        return derivedSuites;
    }

    public static final class NavigableSetSubsetTestSetGenerator<E>
            extends SortedSetSubsetTestSetGenerator<E>
    {
        public NavigableSetSubsetTestSetGenerator(
                TestSortedSetGenerator<E> delegate, Bound to, Bound from)
        {
            super(delegate, to, from);
        }

        @Override
        NavigableSet<E> createSubSet(SortedSet<E> sortedSet, E firstExclusive, E lastExclusive)
        {
            NavigableSet<E> set = (NavigableSet<E>) sortedSet;
            if (from == Bound.NO_BOUND && to == Bound.INCLUSIVE)
            {
                return set.headSet(lastInclusive, true);
            }
            else if (from == Bound.EXCLUSIVE && to == Bound.NO_BOUND)
            {
                return set.tailSet(firstExclusive, false);
            }
            else if (from == Bound.EXCLUSIVE && to == Bound.EXCLUSIVE)
            {
                return set.subSet(firstExclusive, false, lastExclusive, false);
            }
            else if (from == Bound.EXCLUSIVE && to == Bound.INCLUSIVE)
            {
                return set.subSet(firstExclusive, false, lastInclusive, true);
            }
            else if (from == Bound.INCLUSIVE && to == Bound.INCLUSIVE)
            {
                return set.subSet(firstInclusive, true, lastInclusive, true);
            }
            else
            {
                return (NavigableSet<E>) super.createSubSet(set, firstExclusive, lastExclusive);
            }
        }
    }

    @Override
    public NavigableSetTestSuiteBuilder<E> newBuilderUsing(
            TestSortedSetGenerator<E> delegate, Bound to, Bound from)
    {
        return using(new NavigableSetSubsetTestSetGenerator<E>(delegate, to, from));
    }

    /**
     * Create a suite whose maps are descending views of other maps.
     */
    private TestSuite createDescendingSuite(
            FeatureSpecificTestSuiteBuilder<?, ? extends OneSizeTestContainerGenerator<Collection<E>, E>>
                    parentBuilder)
    {
        TestSetGenerator<E> delegate =
                (TestSetGenerator<E>) parentBuilder.getSubjectGenerator().getInnerGenerator();

        List<Feature<?>> features = new ArrayList<>();
        features.add(DESCENDING_VIEW);
        features.addAll(parentBuilder.getFeatures());

        return NavigableSetTestSuiteBuilder.using(
                        new TestSetGenerator<E>()
                        {

                            @Override
                            public SampleElements<E> samples()
                            {
                                return delegate.samples();
                            }

                            @Override
                            public E[] createArray(int length)
                            {
                                return delegate.createArray(length);
                            }

                            @Override
                            public Iterable<E> order(List<E> insertionOrder)
                            {
                                List<E> list = new ArrayList<>();
                                for (E e : delegate.order(insertionOrder))
                                {
                                    list.add(e);
                                }
                                Collections.reverse(list);
                                return list;
                            }

                            @Override
                            public Set<E> create(Object... elements)
                            {
                                NavigableSet<E> navigableSet = (NavigableSet<E>) delegate.create(elements);
                                return navigableSet.descendingSet();
                            }
                        })
                .named(parentBuilder.getName() + " descending")
                .withFeatures(features)
                .suppressing(parentBuilder.getSuppressedTests())
                .createTestSuite();
    }

    @Override
    protected List<Class<? extends AbstractTester>> getTesters()
    {
        List<Class<? extends AbstractTester>> testers = Helpers.copyToList(super.getTesters());
        testers.add(NavigableSetNavigationTester.class);
        return testers;
    }
}
